The Brazilian army and the low prevalence of sexually transmitted infections in women of the military garrison of Campinas between 2017 to 2020: a prospective, cross-sectional epidemiological study

ABSTRACT BACKGROUND: Given the characteristics of military missions, intense interpersonal contact, and wide variation in casual relationships, the military has long been recognized as a high-risk population for sexually transmitted infections (STIs). OBJECTIVE: To assess the prevalence of STIs and socioepidemiological profile of women in the military garrison of Campinas. DESIGN AND SETTING: This prospective, cross-sectional epidemiological study, assisted by the Health Fund in the military garrison of Campinas, assessed the prevalence of human immunodeficiency virus (HIV), hepatitis B and C, syphilis, human papillomavirus (HPV), chlamydia, and gonococcus in military women or companions of soldiers with active or previously active sexual life. METHODS: This study included 647 women based on the non-inclusion criteria. They underwent clinical and laboratory tests for diagnosis of STIs. For statistical analysis, patients were divided into groups according to the presence or absence of STIs and into age groups. RESULTS: Most women were military dependents, and the majority were asymptomatic. The prevalence of STIs, in ascending order, was 0.3% for hepatitis B and C, 0.62% for syphilis, 0.62% for gonorrhea, 1.08% for chlamydia, and 2.63% for HPV. There were no cases of HIV infection. CONCLUSIONS: The Brazilian Army has the most women-like dependents in the military, belonging to the hierarchical circle of the squares. Early onset of sexual activity favored STIs approximately twice, and younger women had approximately seven times more chlamydia infections. In the general population studied, the prevalence of STIs was lower than expected than in the armed forces of other nations.


INTRODUCTION
In the armed forces, the characteristics of the missions, intense interpersonal interactions, wide variations in casual relationships, and long periods of abstinence and transit favor sexually transmitted infections (STIs). Historically, STI rates among military personnel in the United States have been higher than those among civilians. 1 Young male soldiers are likely to be the main vectors of STIs, which can increase transmission to young military women and dependents, since close coexistence can stimulate affective and sexual bonds. Irregular use of condoms can also have a significant impact. Chao et al. demonstrated that 25% of the Brazilian population had sexarche before 15 years of age, and another 35% between 15-19 years of age. In the same survey, the regular use of condoms was unsatisfactory, with only a 39% use among people aged 15-64 years. [2][3][4] A large survey of women in the United States military identified a 9.2% prevalence of chlamydia infection among female recruits, with a peak of 12.2% at 17 years of age. Prevalence declined markedly with increasing age, dropping to 5% for women over 25 years of age. 5 In Brazil, there are few studies relating military behavior to STIs or any other diseases. Since 1996, the Brazilian Department of Sexually Transmitted Infections, STI-AIDS and Viral Hepatitis, has conducted probability sampling surveys to determine the prevalence of human immunodeficiency virus (HIV), hepatitis B and C, and syphilis by assessing sexual and risk behaviors among recruits aged 17-22 years old from the Brazilian Army using questionnaires. 6 Currently, one of the major concerns in the Brazilian Army is the sexual health of women who begin their military career very early (between 17 and 20 years of age in the military line). 9 According to the Pan American Health Organization, half of the new HIV infections arise in children under 24 years of age, with the majority being sexually transmitted. 10,11 According to a recent study in the United States, STIs are on the rise in the United States military, and women are more affected than men by all infections except syphilis. Younger soldiers, aged ≤ 24 years, are affected by most of the diseases at higher rates than of any other age group. 12 Women are a growing number within the Armed Forces; however, militarism is still a male-dominated space in which the woman has a marked place as the wife and partner of the military husband. [13][14][15][16] In the Brazilian Army, female soldiers make up 3.2% of the

RESULTS
The 647 women included in this study were military personnel, sexual partners of military personnel, and dependents. The mean age was 38 years ± standard deviation (SD) 16.13. Their minimum and maximum ages were 14 and 93 years, respectively. The analysis was conducted from 2017 to 2020. In the last year, there was a significant decrease in visits, with a consequent decrease in the number of women who could be evaluated due to the beginning of the coronavirus disease-2019 pandemic.
In the general population studied, the prevalence of STIs, in increasing order of incidence, was 0% for HIV, 0.3% for hepatitis B and C (2 cases), 0.62% for syphilis (4 cases), 0.62% for gonorrhea (4 cases), 1.08% for chlamydia (7 cases), and 2.63% for HPV (17 cases). As there were no cases of HIV infection, this information has been removed from the tables and graphs. The frequency of infection found in the group of 30 women with 34 diagnosed STIs was 5.89% for hepatitis B and C, 11.77% for syphilis, 11.77% for gonorrhea, 20.58% for chlamydia, and 50% for HPV ( Table 1).
In the general epidemiological assessment, the largest number About rank or graduation, in the lowest age group, there was a preponderance of "soldiers" (63.47%) and in the highest, there was an almost equal division between "enlisted" and "officers, " with 52.7% and 47.29%, respectively (P = 0.0159). Thus, according to the hierarchical circle to which the woman belonged, we had a general preponderance of the "enlisted" circle, with about 11% more than the circle of officers. Regarding age groups, the largest proportion of the enlisted circle was more evident in the group of people under 25 years old, with almost 30% more than the circle of officers. In the older age group, the proportions were similar between the two groups. The results were statistically significant for these data ( Table 2).
Of the 30 women diagnosed with STIs, 18 were younger than 25 years and 12 were 25 years or older. The largest number also corresponded to military dependents, with 23 women (76.67%), followed by seven (23.33%) full-time military personnel and, finally, no pensioners, but without statistical significance between the types of attachment, hierarchical circles, and age groups ( Table 2). The mean age in this group was 36.9 years (± SD 10.46), with a minimum and a maximum age of 17 and 59 years, respectively.
By subtracting the infected women from the 647 women studied, we created a WITHOUT-STI group with 617 women. We then In the WITH-STI group, more than half of the population studied was nulliparous, the rest had between one and three children, and no woman had more than three children. The number of abortions was almost five times higher in the WITHOUT-STI group, which was a statistically significant finding (P = 0.00007) ( Table 3).
The number of partners was restricted to 10 for approximately 80% of women in both groups. However, the percentage of women in the WITH-STI group was approximately seven times higher (P = 0.00343) when they had 11 or more partners ( Table 3).
Most women in the WITHOUT-STI group had established relationships, while most women in the WITH-STI group did not have a steady partnership, though this data was not statistically significant ( Table 3).

An earlier age of sexual initiation (17 years or less) favored the
presence of STIs about 1.5 times more and almost 2 times more when sexarche occurred at 14 years or less. (Table 3) Most women (75%) were asymptomatic and went to consult

DISCUSSION
This study is unprecedented in the Brazilian Armed Forces.
Previous studies have only involved young, conscripted men entering mandatory military service. The military garrison of Campinas consists of more than 7,000 beneficiaries of the Brazilian Army Health Fund, including approximately 2,600 active-duty military men and women.
Most of the women treated as outpatients sought preventive gynecological consultations, and 75% of them were asymptomatic.
These data are consistent with the profile of the Brazilian female population, which is more concerned about health than the male population. Genital discharge was the most frequent complaint, particularly in younger patients.
Due to the type of activity developed, some military women and companions of military men are more likely to be involved in high-risk sexual practices and contract STIs for the following reasons: less use of barrier contraception, little knowledge about gynecological health, and lower education level. [18][19][20][21] However, a bias that we can point out for the population studied is the fact that the military garrison is located in a region of greater purchasing and educational power with a high human development index (the Campinas region), which may explain  [23][24][25][26] According to the World Health Organization, adolescence is a fundamentally biological process that occurs in individuals aged between 10 and 19 years. A survey found that 49.25% of the investigated adolescents had already started their sexual lives.
The occurrence of the first intercourse before 15 years of age was observed in approximately 30% of these individuals. These data are similar to those of other studies that revealed that most adolescents experience their first sexual intercourse at this age. Early sexual initiation is considered a risk factor, as is the number of sexual partners exposed to STIs. 23 Like the GENERAL population, the STI group in its entirety (100%) had between 0 and 3 children, 60% of whom were nulliparous. Therefore, the presence of STIs did not increase the number of abortions, since women without STIs had approximately five times more abortions than women with STIs. Again, military habits that involve military families seem to favor family planning as well as the prevention of STIs. Additionally, of the 483 women, approximately 1% were diagnosed with a lowgrade lesion in the uterine cervix and 0.21% with a high-grade lesion as the final diagnosis.
There were three cases of concomitant STIs, totaling 34 infections in 30 women: one woman with HPV associated with Chlamydia and Gonococcus and the other two with Chlamydia and Gonococcus.
The ratio of Chlamydia to gonorrhea infection in both age groups tended toward 2:1. The group of patients younger than 25 years showed a tendency toward a higher proportion of every sexual disease studied except for hepatitis. Chlamydia was more frequent in women under 25 years of age (P = 0.0144), while gonorrhea showed a similar trend (P = 0.0549). (Table 4, Graph 1) When the same age comparison in women with STIs was made, HPV was significantly more prevalent in older women than in younger women (P = 0.00158).